Many microwave popcorn popping constructions in current commercial use are multi-ply paper bags in which inner and outer flexible paper sheets are laminated to one another, typically with a microwave interactive construction (sometimes referred to as a microwave susceptor) encapsulated between the two flexible paper sheets or plies. Popcorn popping bags of this type are described, for example, in U.S. Pat. Nos. 4,904,488; 4,973,810; 4,982,064; 5,044,777; 5,081,330; 5,753,895; 5,928,554; and, 6,396,036. The complete disclosures of these eight patents are incorporated herein by reference.
A common feature of such constructions is that they are generally made from relatively flexible paper materials. Typically, when a two-ply arrangement is used, the inner ply is a greaseproof or grease-resistant paper, the preferred inner ply being a flexible paper material having a basis weight no greater than about 25 lbs. per ream, typically within the range of 20-25 lbs. per ream. In such instances, it can be a fluorochemical treated paper or other treated paper having a grease resisting characteristic. Grease resistance can be determined using a test called the Scotchban® test, which defines an acceptable level of grease resistance from industry to industry. For microwave popcorn packaging constructions, a material is considered “grease resistant” if, under the Scotchban test, it has a grease resistance of minimum kit 8. A useable material is a grease proof paper known as RHI-PEL 250, available from Rheinlander Paper Company of Rheinlander, Wis. 54501. A useable fluorochemical treatment is Ciba Lodyne 208E from Ciba Specialty Corporation North America, High Point, N.C. 27261-2444.
The outer ply is typically a 21 lb. bleached Kraft paper.
Using these common two-ply construction techniques, the resulting microwave popcorn container constructions can be provided in a bag form that is: (a) collapsed and folded when stored before use; (b) can be unfolded and expanded during a popping operation, when a popcorn charge therein is exposed to microwave energy in a microwave oven; and, (c) can be collapsed for disposal, once used. Since the materials are constructed such they can be collapsed and folded, the arrangements can be easily manufactured, filled, shipped and stored. Because the materials allow for the unfolding for use and expansion during popcorn popping, a convenient popcorn popping and dispensing container is provided.
An issue with many current commercially available microwave popcorn bag constructions, for example of the type characterized in the previously recited (eight) patents, relates to certain of the same basic features that provide advantage, i.e., the flexible, collapsible and foldable nature of the bag constructions. In particular, in many instances consumers wish to eat the popcorn from a relatively rigid walled, upright, bowl construction, as opposed to a flexible paper, foldable, expandable/collapsible construction.
A variety of alternative microwave popcorn package arrangements, utilizing rigid walled containers, in the shape of a bowl or tub, are available. Some examples are described in U.S. Pat. Nos. 5,008,024; 5,097,107; and 5,834,046. The complete disclosure of these three patents is also incorporated herein by reference.
A shortcoming of the tub configurations of the types characterized in the identified patents stems in part from some of the same features that provide advantageous operation as a tub. That is, the relatively rigid three-dimensional structure of the tub walls and bottom is inconvenient to package, ship and store.